<!DOCTYPE html>
<html lang="en">

<head>
    <title></title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">

    <style>
        .ball {
            width: 15px;
            height: 15px;
            border-radius: 50%;
            background-color: red;
        }
    </style>
</head>

<body>
    <div id="app">
        <input type="button" value="欸嘿嘿" @click="flag=!flag">
        <transition 
        @before-enter="beforeEnter"
        @enter="enter"
        @after-enter="afterEnter">
            <div class="ball" v-show='flag'></div>
        </transition>
    </div>
    <script src="./node_modules/_vue@2.5.22@vue/dist/vue.js"></script>
    <script>
        var vm = new Vue({
            el: '#app',
            data: {
                flag:false
            },
            methods: {
                beforeEnter(el){
                    el.style.transform = 'translate(0,0)'
                },
                enter(el){
                    //这句话无实际作用，但是不写，出不来动画效果
                    el.offsetWidth
                    el.style.transform = 'translate(150px,450px)'
                    el.style.transition = 'all 1s ease'
                    // done()
                },
                afterEnter(el){
                    this.flag=!this.flag
                }
            },
        })
    </script>
</body>

</html>